Incredibly pleased and impressed with you providing a downloadable and printable schematic and layout. I am on the hunt for a new build and just found your channel.
Super cool! After years of watching, reading and learning I'm about to start my first champ-ish amp from scratch and I'm still finding new useful videos :D
The Fender Champ, along with several Fender guitar amps, were lifted, or purchased, directly from Bell Telephone and RCA Labs. My 1955 Fender Champ had a sticker on the chassis stating circuit copyright Bell Telephone Labs.
Thanks for commenting. Yes, a lot of the original circuits were “borrowed” from publications. RCA for example published literature on how to employ their tubes hoping people would purchase their tubes to make the circuits. Many companies did this not just Fender. Cheers.
Great video and a great project. This would be a good project for a first time builder. I am building a Champ style 5f1 amp and one thing that's challenging about that is the chassis is about half the size of yours so things are very cramped but this project has a much roomier chassis with which to work. Can't wait to watch the other parts of this project.
Thanks for commenting. Yes, I've built a few Champs before and things can get a bit tight in those smaller chassis. The amp in this video could be easily modified for different output tubes. There is lots of space to experiment! Cheers.
Thanks for commenting. Glad you liked the video. The output section is an old topology from the 40's called Cathode-Coupled Output Stage (aka Self Split) Though, it's not super efficient it works great in this application. There is a link in the video's description section explaining how it works. Cheers
This would be cool if you could do a Marshall 59SL or/and a 2204 master volume. The chassis would have been easier to do if the sides were attached and bent into place, then you would only need to weld is the short vertical corners.
@mikefreda Thanks for this video! Just a heads up that the Input Resistor to ground of the Layout and the Schematic are different. The schematic and parts list say 1 meg, where the Layout says 100R. I'm ordering both, but care to elaborate? Thanks! :)
Hi, I do not know anything about electronics, but I find the idea of building my own guitar amp really cool. Do you have an idea where i can start learning?
There are a lot of content online about how amps work and the Theory. Guitar amp forums are good resources. Uncle Doug’s RUclips channel is good. Even buy a kit (like a champ from Mojotone) and just building it. Read the forums about that exact amp. Cheers.
A complete build document will be uploaded with the Part 3 video when everything is finalized and I'm satisfied with the complete build. I’m working on that video right now. What are you specifically looking for?
Very interesting, thanks for making the video and sharing. I've been researching to use a box pan brake for making chassis. After watching your video I'm wondering about using a welder instead. Could you tell me the equipment you are using for this project? Like the welder setup used at 7:28 and the weld grinder at 8:13 also rods you are using and anything else you think might be relevant? Then I can look into this approach. Thank you.
Thanks for the comments. Yes, a Pan Break is something I may purchase if I do more of these sort of projects. The welder I use is a Miller Maxstar 200 TIG welder. 3/32 Tungsten, ~75 amps, 0.35 mild steel rod. You may be able to find a less expensive TIG welder but a MIG welder is a lot cheaper and easier to learn. TIG welding takes a lot of practice. I've been TIG welding for ~15 years and still learning things. The 90 deg grinder is a Milwaukee M12 Fuel with a 80 Grit Flap disk. I LOVE this tool! It's well worth it! Cheers.
@@MikeFreda Hi Mikes, thanks for the reply. Just had a quick look on TIG welding, en.wikipedia.org/wiki/Gas_tungsten_arc_welding seems there are various safety hazards, so think will stick with the idea of a suitable box pan brake, but might make more economic sense to have a case made up, if can't get ready made off the shelf. Thanks again, enjoyed the vids and have subscribed and liked. You are one smart guy :)
You're welcome. Yes, welding does have some health risks but they can be mitigated with Proper ventilation, Respirators, Good quality helmet and how your clean and prep the material. Hammond makes pre-made cases and chassis that can be easily converted into amp chassis. Cheers.
Thanks for commenting. Yes, I should have. It’s not bad at all. It pretty much sits in my office. When building it I wasn’t sure how it was going to turn out. When I started testing it I was blow away how good it sounded and decided to finish it up nice… I didn’t want to take it all apart to paint the inside. Oh well. Cheers.
@@MikeFreda even tho it will be inside it will still rust I don’t where you live or how humid your area is , yes it does sound good, I’m not sure if you’ve heard or Terry at D- Lab or watched any of his videos, he built me a 3 Watt amp from a repurposed Toyo radio it also sounds very good, I would hate to see such a good sounding amp rust away how about if use some rust oleum and brush the underside it wouldn’t take that long , anyway happy playing
Thanks. I just got a used Blues Jr and am in the process of putting in a Texas Heat speaker. This may seem simple but it is an adventure for me. It obviously sat around as dust was in the cab. My question, instead of making the box and drilling, can you buy this stuff in units so that it is more like gathering the parts and assembling them with your schematic? Thanks Mike You might want to look at the SCHITT VALI 2-I have my headphones plugged in now.
Thanks. Well, this amp was a budget build. I had most of the parts left over from old project. I suspect if I had to by all the parts new the cost would be around $225-250. The transformers and electrolytic capacitors are the expensive parts.
Thanks for your comments. The eyelets in the video are typically used for clothing. I’ve also used ones for PCB’s and they look the same to me. My only comment is the clothing ones are a bit bigger and you should clean/sand them to remove any oxidation before soldering.
Great video! I love the welded chassis. I have a question - it looks like you used mild steel, as opposed to chrome plated or stainless. Are you concerned about corrosion on the inside where it isn’t painted?
Thank you for the comments. Yes, it is mild steel. No, I’m not concerned about corrosion. The amp stays inside and all the grounds are through drilled with stainless hardware. It may rust a bit from me touching it but I don’t feel it’s a major concern. That being said, In my latest amp build I did paint the inside for a cleaner look. So, there is nothing to stop you from doing it as long as you have a good ground. Yes, Chrome plated, aluminum or stainless is another option but that’s hard to work with.
If you have the welding gear and clued up on using it that's the cheapest and fastest way to get a tough chassis. A folding brake will only fold certain pricey grades of aluminium or thin steel sheet but its fiddly if you cut out the corners for the folds and leave tabs to pop rivet the corners together. Hammond make a wide range of nice folded chassis sizes but that can get pricey.
Do you believe tube rectification vs. Solid State makes a difference in tone ? I'm building a 8 watt amp using 2 6AQ5's, a 12AX7 and a SS full bridge rectifier looking for that sweet valve sound.
Yes, I think so. If you had Like-for-Like amps and the only thing different was the Rectification you would hear a slight difference. As for overall Tone, not sure. SS rectification has less sag and typically yields you a higher B+ since there is less of a voltage drop. That being, if I was building a retro tube amp (like a tweed Deluxe) I would keep the tube rectifier. If I was just building a modern amp or just experimenting, SS is cheaper and easier to do and may also be a bit quieter since you can use higher value filter caps.
Really cool! I'll be looking forward to the next installment. Question: How difficult would it be to use a Hammond 269EX power transformer in this build? I've got one built into a Firefly amp and I'm not all that jazzed about its sound. I'd like to try using a different schematic with this transformer and the Hammond 125A I've got too.
Good day. The new video will be up soon. I’m currently working on it. Yes, the Hammond 269EX should work. The voltage may be a bit low but you should be able to adjust the filter dropping resistors to suite. I should be able to recommend a value once I’ve built mine. The amp I’m building should have a “champ” style overdrive tone and not a high gain tone.
@@MikeFreda That's fantastic. Any help with values would be super. Also, you've gotta love the Champ overdrive! It's found its way onto so many classic songs. Looking forward to seeing the next video. Also, I love the way you welded up your own chassis. Very DIY! No possibility of having to cram stuff into an undersized Hammond enclosure since you're making it custom.
Nice content! Just subd. just started to read into amp building and modding. I have a 15watt Hayden tube amp that im planning to mod into a Friedman jj jr., Can i leave the phase inverter, output section, and power section as is, and just mod the preamp section? Thanks!
Thank you. I’m not familiar with those two amps. Can’t really comment. There is nothing to stop you from tweaking the preamp circuit a bit with some different values. You may get something you like.... you may not. At the end of the day that’s how some tweakers got into business.
Thanks for commenting. I do not know if it is possible with a 12AU7. I've never done it. That low of B+ is not represented on the documented load line. It may work but the output would be low and possibly distorted. Look at Usagi Electric RUclips channel. He experiments with low Voltage Vacuum Tube Audio Amplifier. Cheers.
Yes, you can. It will work but it will be very clean sounding and will not distort very much. A 12AU7 has a mu (Amplification Factor) of 20. a 12AX7 has a mu of 100. That is a big difference in voltage gain and thus the overall sound of the amplifier.
This amp is not designed to have higher wattage. You would need to go with a different design with larger power transformer and output transformer. SE 6V6 or 6L6 with power scaling would be something to look for. I think MOJO and Weber offer a kit like that. Yes, effects loop can be added but I made this amp to be simple, low cost and easy to make.
Just sitting through the 14 minute painting advert, paint pokemon. I hope the advertisers give you the due amount! Nice build indeed. Would like to know where to get one of those push pull output transformers? Also, I've never seen a phase splitter arrangement like the one in this amp. Does it somehow couple to the other part of the tube through cathode coupling, of similar?
Thanks for the comments. The add revue is not a lot by any means. I just helps pay a small portion of the project and video equipment. As you now, tube amps can be little pricey to build. The output transformer is very common. It's made by Hammond and I got is from Mouser. Mojotone make a higher quality one as well. It’s just a small Push/Pull good for a few watts. This way of Phase splitting is also called Cathode-Coupled Output Stage. It’s a very old method (circa 1940’s) which is actually not that efficient but with a lower powered amp it doesn’t really matter since we are not looking for a lot of output in this application. This circuit is where one output tube derives it’s input by cathode-coupling from the other. I hope that helps?
@@MikeFreda Many thanks! I started building single ended small amplifiers for something to do during my oncoming retirement. I don't have much experience with tube push pull output, so if I can get one of the transformers at a reasonable price, might start exploring class B push pull. Your 1 watt amp project is gr8 for practice and sounds really nice, too! (o:
Terrific video, Mike! I was wondering how you arrived at the 12bh7 as your choice for output tube. Also, where did you find the threaded inserts that you used in the corners, for attaching the bottom plate? I was looking for something like that for rack gear that I'm building.
Thanks for your comment. The 12BH7 is very similar to the 12AU7. The 6CG7 could also work. These tubes have a low Mu (~20) which makes it good for this application. It is stated that the 12BH7 is a "tougher" tube than a 12AU7 and has higher dissipation characteristics. You can use a 12AU7 but you should probably lower the bias and need to use different primary taps on the OT. The threaded inserts are call Rivnuts. You can install them with a simple tool or a proper gun. You can get them at Harbour Freight and they are all over Amazon. The cheap tools work okay but they can get a bit frustrating.
@@MikeFreda Thanks, Mike. I was wondering about use of a pentode for the output, but I suppose that would require more engineering. There was a series of half-rack 'pedals' by H&K that used various tubes to drive a dummy load and speaker simulator. One used an EL84, another used a 12au7. They'd also drive a speaker. Probably very pricey now. 'Rivnuts'...I searched for a couple hours for 'threaded inserts' and whatever else I could think of, and never came up with Rivnuts. You saved me some time. Those should be perfect for the rack systems.
Hello, thanks for reaching out. Unfortunately, I do not sell kits. There really is no money in it for me since I have to buy all my parts at full retail. I’m not familiar with a micro terror but I suspect it’s a higher gain amp. Would be fun to build but higher gain amps can be tough to make quiet and not buzz/fizz. Stay tune, I am making a one watt fumble style amp. There will be a video of it soon.
Hello, unfortunately, $200 would barely cover the cost of the parts. The issue is that I have to purchase everything retail and pay for shipping. You should give it a try.
Use copper strings with magnets glued on the strings because I'm the anti guitar guy who never had patience to learn guitar because I didn't think stealing someone's girlfriend as a fake rock star was worth it long term. I made most of the circuit with parts hanging in the air just to see how fast I could make it on those white multi connector legs with screws. Smashing a guitar into an amp would be my ultimate high/townsend/moon.
Hello, not yet. I’m still tweaking a few things. There is a link to the build schematic in the Description section. This is what I used to build the amp in the first two videos. The Part 3 video will wrap everything up. Cabinet and final schematic and parts list.
Hello, you can but I’m not sure it is worth modifying the circuit to make it work. You sort of lose the champ/Princeton vibe of the amp. It’s has a simplified topology where you can just input the effects right at the input Jack. You can look on the net for people who have done it. The front end of this amp is pretty much a 5F1 Champ. Some have put it between the two preamp stages or just before the power tube stage. I have not clue what would sound best or it if actually works since I’ve never done it. I hope that helps a bit?
@@MikeFreda thanks, you make a valid point. So yeah, it makes sense to keep this amp as simple as possible. Or, if I need something more versatile, go fore a Tweed Deluxe build. Except I'm not sure that one has an fx loop either. Not in early versions for sure.
Most of the earlier tube amps (40’s to early 60’s) did not. Effects weren’t a thing back then due to solid state components weren’t really invented yet and people wanted a clean sound…. It’s wasn’t till the 60’s effects started to take off. All the tweed amps are basic topology based from the 40’s and 50’s.
@@MikeFreda yup. I once had the bright idea of experimenting with turning an old Soviet tube radio into a guitar amp, looked at the schematic and the damn thing creeped me out. Wasn't too keen on having tube high voltage rails on common ground with the guitar, because the transformer didn't have separate leads to isolate those. In our business, the first thing you learn is to respect high voltage, least it's the last thing you learn to respect.
Are you asking me about 220vac line voltage? If so, Hammond Transformer make a dual primary voltage power transformer. I think it’s their 300’s series.
Thanks for commenting, a 12BH7 in a single SE configuration would only give you ~1/3 of a watt depending how it is biased. In a Push/Pull or Parallel SE configuration you would only get around 1 watt. These tubes weren't really designed for this sort of application but people have figured out of the years that it can handle this duty. If you want more power, you will need a use a dedicated power tube like a 6V6 or a EL84. Cheers
@@MikeFreda thanks Mike for confirming. I asked only because on the Blackstar HT5 they use a 12BH7 to get 5W. I wasn't sure how the whole thing worked…
You’re welcome. I suspect that is a bit of a marketing ploy. 1watt RMS without clipping is different than 5watt peak at a higher frequency range. They don’t really say how or what their measurement is. Realistically, to your ear, the difference between 1 watt RMS and 5 watt peak is not a lot. Cheers.
Thanks for the comment. I wanted a low power practice/recording amp. I have made a couple larger amps and I find I don’t play them much. Also, larger amps do cost a lot more to make. The transformers and tubes cost twice as much. This video was also trying to show people that you can morph circuits and make your own creation.
It is and it isn't. My first builds were pretty messy and a bit of a rats nest but you only get better by doing. What you see me doing is 20+ years of building things. Just do it. Learn, improve and have fun.
Mate, even just watching you weld and grind the chasis is so satisfying..
Thanks. Cheers.
Incredibly pleased and impressed with you providing a downloadable and printable schematic and layout. I am on the hunt for a new build and just found your channel.
Thanks for commenting. Glad you found my content helpful. Cheers.
Super cool! After years of watching, reading and learning I'm about to start my first champ-ish amp from scratch and I'm still finding new useful videos :D
Awesome great to hear. Thanks for the feedback.
The Fender Champ, along with several Fender guitar amps, were lifted, or purchased, directly from Bell Telephone and RCA Labs.
My 1955 Fender Champ had a sticker on the chassis stating circuit copyright Bell Telephone Labs.
Thanks for commenting. Yes, a lot of the original circuits were “borrowed” from publications. RCA for example published literature on how to employ their tubes hoping people would purchase their tubes to make the circuits. Many companies did this not just Fender. Cheers.
Duuuude. I’m stoked to follow this build. And am uber glad I finally found you.
Thanks for the content!
Glad you enjoy it! Cheers.
Great video and a great project. This would be a good project for a first time builder. I am building a Champ style 5f1 amp and one thing that's challenging about that is the chassis is about half the size of yours so things are very cramped but this project has a much roomier chassis with which to work. Can't wait to watch the other parts of this project.
Thanks for commenting. Yes, I've built a few Champs before and things can get a bit tight in those smaller chassis. The amp in this video could be easily modified for different output tubes. There is lots of space to experiment! Cheers.
Cool! Never saw eyelets like those! Never saw welding up a chassis! Most guys just bend with whatever they can come up with!
Retired EE here, I like the fact that you have some negative feedback in your circuit design. I'm impressed, a very well thought out design.
Thanks. I like the having the option. Realistically, I’d probably make the resistor value even lower to get a more noticeable effect.
True craftsman. I feel bad ill never do this in my life
Thanks.
Why not?
Nice work ,sir!
Leaving a comment, because…you know…comment. Maybe leave another one later, but this one is just to support the channel. Cheers (that’s the comment.)
Thanks! Till next time! Cheers.
Super cool were my words too. I'd really like to find a super easy amp kits to start with.
Thanks for your comment. Weber and Mojotone sell easy/simple amp kits for a reasonable cost.
Can't wait to see how you handle the phase inversion for your push pull output section. Nice video and very watchable narration.
Thanks for commenting. Glad you liked the video. The output section is an old topology from the 40's called Cathode-Coupled Output Stage (aka Self Split) Though, it's not super efficient it works great in this application. There is a link in the video's description section explaining how it works. Cheers
Subbed . Looking forward to this series!
Awesome, thank you!
good series, thanks
Thank you. It is a cool little amp. I’m planning to expand on this idea. Cheers.
Amazing what you can learn from a couple RUclips videos.
Nice build! I like the painted chassis idea.
Thanks. I’m happy the way it turned out. The only issue is waiting for the paint to cure.
Just start off with a C Purlin channel section. 300x 90x 2.4mm. Cut to length then cap the sides and plate the open side.
This would be cool if you could do a Marshall 59SL or/and a 2204 master volume. The chassis would have been easier to do if the sides were attached and bent into place, then you would only need to weld is the short vertical corners.
Thanks for your comment. Yes, I’m in the process of building a higher gain 1watt amp like you describe. New video will be up in the new year.
Now i know why tube amps are expensive. Lots Of parts even though its only a low wattage and the talents to assembled it.
Yes, this is very true. That's why a lot of people like kits or try to scratch build. You can save some money if you do the labour yourself, cheers!
Great build project video. Just found your channel. Subscribed.
Thanks. Was a fun little project. I’m thrilled on how it turned out.
nice!!!
Good Night my Youth A beautiful project Can you share the schematics? Thanks
nice amp, michael de santa.
Thanks. More cool amps like this is coming to my channel. Cheers.
You should make that eyelet punch longer handle'd, might make it easier to use. (my 2¢) this all good
@mikefreda Thanks for this video! Just a heads up that the Input Resistor to ground of the Layout and the Schematic are different. The schematic and parts list say 1 meg, where the Layout says 100R. I'm ordering both, but care to elaborate? Thanks! :)
Thanks for pointing it out. I thought I had corrected the PDF. It is 1meg. It is fixed now! Cheers
Hi, I do not know anything about electronics, but I find the idea of building my own guitar amp really cool. Do you have an idea where i can start learning?
There are a lot of content online about how amps work and the Theory. Guitar amp forums are good resources. Uncle Doug’s RUclips channel is good. Even buy a kit (like a champ from Mojotone) and just building it. Read the forums about that exact amp. Cheers.
@@MikeFredaGreat! Thanks for the answer.
It would be awesome if you would actually put the links in the discription. Have a great day.
A complete build document will be uploaded with the Part 3 video when everything is finalized and I'm satisfied with the complete build. I’m working on that video right now. What are you specifically looking for?
Very interesting, thanks for making the video and sharing. I've been researching to use a box pan brake for making chassis. After watching your video I'm wondering about using a welder instead. Could you tell me the equipment you are using for this project? Like the welder setup used at 7:28 and the weld grinder at 8:13 also rods you are using and anything else you think might be relevant? Then I can look into this approach.
Thank you.
Thanks for the comments. Yes, a Pan Break is something I may purchase if I do more of these sort of projects. The welder I use is a Miller Maxstar 200 TIG welder. 3/32 Tungsten, ~75 amps, 0.35 mild steel rod. You may be able to find a less expensive TIG welder but a MIG welder is a lot cheaper and easier to learn. TIG welding takes a lot of practice. I've been TIG welding for ~15 years and still learning things. The 90 deg grinder is a Milwaukee M12 Fuel with a 80 Grit Flap disk. I LOVE this tool! It's well worth it! Cheers.
@@MikeFreda Hi Mikes, thanks for the reply. Just had a quick look on TIG welding, en.wikipedia.org/wiki/Gas_tungsten_arc_welding seems there are various safety hazards, so think will stick with the idea of a suitable box pan brake, but might make more economic sense to have a case made up, if can't get ready made off the shelf. Thanks again, enjoyed the vids and have subscribed and liked. You are one smart guy :)
You're welcome. Yes, welding does have some health risks but they can be mitigated with Proper ventilation, Respirators, Good quality helmet and how your clean and prep the material. Hammond makes pre-made cases and chassis that can be easily converted into amp chassis. Cheers.
Cool build , yet you should of painted the underside because it’s going to rust very quickly
Thanks for commenting. Yes, I should have. It’s not bad at all. It pretty much sits in my office. When building it I wasn’t sure how it was going to turn out. When I started testing it I was blow away how good it sounded and decided to finish it up nice… I didn’t want to take it all apart to paint the inside. Oh well. Cheers.
@@MikeFreda even tho it will be inside it will still rust I don’t where you live or how humid your area is , yes it does sound good, I’m not sure if you’ve heard or Terry at D- Lab or watched any of his videos, he built me a 3 Watt amp from a repurposed Toyo radio it also sounds very good, I would hate to see such a good sounding amp rust away how about if use some rust oleum and brush the underside it wouldn’t take that long , anyway happy playing
Thanks. I just got a used Blues Jr and am in the process of putting in a Texas Heat speaker. This may seem simple but it is an adventure for me. It obviously sat around as dust was in the cab. My question, instead of making the box and drilling, can you buy this stuff in units so that it is more like gathering the parts and assembling them with your schematic? Thanks Mike You might want to look at the SCHITT VALI 2-I have my headphones plugged in now.
Thanks for the comments. Yes, you can find generic chassis and kits to make whatever you want. Mojo and Weber have stuff like that.
@@MikeFreda Thanks Mike,
I appreciate the advice.
Your channel is a treasure! I feel lucky to find it
I appreciate you thanks
And how much the amp costs you?
Thanks. Well, this amp was a budget build. I had most of the parts left over from old project. I suspect if I had to by all the parts new the cost would be around $225-250. The transformers and electrolytic capacitors are the expensive parts.
Cool, this is basically a little Class A Amp much like the Peavey Royal 8, nicely done, Are the eyelets the ones sold for PCB, or for Clothing?
Thanks for your comments. The eyelets in the video are typically used for clothing. I’ve also used ones for PCB’s and they look the same to me. My only comment is the clothing ones are a bit bigger and you should clean/sand them to remove any oxidation before soldering.
Great video! I love the welded chassis. I have a question - it looks like you used mild steel, as opposed to chrome plated or stainless. Are you concerned about corrosion on the inside where it isn’t painted?
Thank you for the comments. Yes, it is mild steel. No, I’m not concerned about corrosion. The amp stays inside and all the grounds are through drilled with stainless hardware. It may rust a bit from me touching it but I don’t feel it’s a major concern. That being said, In my latest amp build I did paint the inside for a cleaner look. So, there is nothing to stop you from doing it as long as you have a good ground.
Yes, Chrome plated, aluminum or stainless is another option but that’s hard to work with.
Plating will burn off from the welding. Aluminum and stainless can be TIG welded.
If you have the welding gear and clued up on using it that's the cheapest and fastest way to get a tough chassis. A folding brake will only fold certain pricey grades of aluminium or thin steel sheet but its fiddly if you cut out the corners for the folds and leave tabs to pop rivet the corners together.
Hammond make a wide range of nice folded chassis sizes but that can get pricey.
Do you believe tube rectification vs. Solid State makes a difference in tone ? I'm building a 8 watt amp using 2 6AQ5's, a 12AX7 and a SS full bridge rectifier looking for that sweet valve sound.
Yes, I think so. If you had Like-for-Like amps and the only thing different was the Rectification you would hear a slight difference. As for overall Tone, not sure. SS rectification has less sag and typically yields you a higher B+ since there is less of a voltage drop. That being, if I was building a retro tube amp (like a tweed Deluxe) I would keep the tube rectifier. If I was just building a modern amp or just experimenting, SS is cheaper and easier to do and may also be a bit quieter since you can use higher value filter caps.
Really cool! I'll be looking forward to the next installment. Question: How difficult would it be to use a Hammond 269EX power transformer in this build? I've got one built into a Firefly amp and I'm not all that jazzed about its sound. I'd like to try using a different schematic with this transformer and the Hammond 125A I've got too.
Good day. The new video will be up soon. I’m currently working on it. Yes, the Hammond 269EX should work. The voltage may be a bit low but you should be able to adjust the filter dropping resistors to suite. I should be able to recommend a value once I’ve built mine. The amp I’m building should have a “champ” style overdrive tone and not a high gain tone.
@@MikeFreda That's fantastic. Any help with values would be super. Also, you've gotta love the Champ overdrive! It's found its way onto so many classic songs. Looking forward to seeing the next video. Also, I love the way you welded up your own chassis. Very DIY! No possibility of having to cram stuff into an undersized Hammond enclosure since you're making it custom.
Nice content! Just subd. just started to read into amp building and modding. I have a 15watt Hayden tube amp that im planning to mod into a Friedman jj jr., Can i leave the phase inverter, output section, and power section as is, and just mod the preamp section? Thanks!
Thank you. I’m not familiar with those two amps. Can’t really comment. There is nothing to stop you from tweaking the preamp circuit a bit with some different values. You may get something you like.... you may not. At the end of the day that’s how some tweakers got into business.
Amigo cuantos Vatios maximo puede entregar un Amplificador con la valvula 12AU7 si se alimenta con 12V. Se puede aumentar ese voltage?
Thanks for commenting. I do not know if it is possible with a 12AU7. I've never done it. That low of B+ is not represented on the documented load line. It may work but the output would be low and possibly distorted. Look at Usagi Electric RUclips channel. He experiments with low Voltage Vacuum Tube Audio Amplifier. Cheers.
@@MikeFreda Ok. Tal vez sería mejor utilizar el 12AU7 como etapa de Pre-Amplificación. Muchas Gracias por responder.
Yes, you can. It will work but it will be very clean sounding and will not distort very much. A 12AU7 has a mu (Amplification Factor) of 20. a 12AX7 has a mu of 100. That is a big difference in voltage gain and thus the overall sound of the amplifier.
@@MikeFreda Muchas Gracias Amigo.
also any idea how to make it be able to switch from 1w to 5w or 10w. Or possibly adding an effects loop?
This amp is not designed to have higher wattage. You would need to go with a different design with larger power transformer and output transformer. SE 6V6 or 6L6 with power scaling would be something to look for. I think MOJO and Weber offer a kit like that. Yes, effects loop can be added but I made this amp to be simple, low cost and easy to make.
@@MikeFreda its an awesome design and im very excited to build it.
Just sitting through the 14 minute painting advert, paint pokemon. I hope the advertisers give you the due amount! Nice build indeed. Would like to know where to get one of those push pull output transformers? Also, I've never seen a phase splitter arrangement like the one in this amp. Does it somehow couple to the other part of the tube through cathode coupling, of similar?
Thanks for the comments. The add revue is not a lot by any means. I just helps pay a small portion of the project and video equipment. As you now, tube amps can be little pricey to build.
The output transformer is very common. It's made by Hammond and I got is from Mouser. Mojotone make a higher quality one as well. It’s just a small Push/Pull good for a few watts.
This way of Phase splitting is also called Cathode-Coupled Output Stage. It’s a very old method (circa 1940’s) which is actually not that efficient but with a lower powered amp it doesn’t really matter since we are not looking for a lot of output in this application. This circuit is where one output tube derives it’s input by cathode-coupling from the other. I hope that helps?
@@MikeFreda Many thanks! I started building single ended small amplifiers for something to do during my oncoming retirement. I don't have much experience with tube push pull output, so if I can get one of the transformers at a reasonable price, might start exploring class B push pull. Your 1 watt amp project is gr8 for practice and sounds really nice, too! (o:
Terrific video, Mike! I was wondering how you arrived at the 12bh7 as your choice for output tube.
Also, where did you find the threaded inserts that you used in the corners, for attaching the bottom plate? I was looking for something like that for rack gear that I'm building.
Thanks for your comment. The 12BH7 is very similar to the 12AU7. The 6CG7 could also work. These tubes have a low Mu (~20) which makes it good for this application. It is stated that the 12BH7 is a "tougher" tube than a 12AU7 and has higher dissipation characteristics. You can use a 12AU7 but you should probably lower the bias and need to use different primary taps on the OT. The threaded inserts are call Rivnuts. You can install them with a simple tool or a proper gun. You can get them at Harbour Freight and they are all over Amazon. The cheap tools work okay but they can get a bit frustrating.
@@MikeFreda Thanks, Mike. I was wondering about use of a pentode for the output, but I suppose that would require more engineering. There was a series of half-rack 'pedals' by H&K that used various tubes to drive a dummy load and speaker simulator. One used an EL84, another used a 12au7. They'd also drive a speaker. Probably very pricey now.
'Rivnuts'...I searched for a couple hours for 'threaded inserts' and whatever else I could think of, and never came up with Rivnuts. You saved me some time. Those should be perfect for the rack systems.
Yes, you can use a pentode like a 6V6 in the output, that’s basically and Fender Champ or Princeton. You would need a different PT and OT. Cheers!
Hi Mike, I was wondering if you sold any of your amp kits or did custom builds? I'm looking for an amp head similar to the Orange Micro Terror.
Hello, thanks for reaching out. Unfortunately, I do not sell kits. There really is no money in it for me since I have to buy all my parts at full retail. I’m not familiar with a micro terror but I suspect it’s a higher gain amp. Would be fun to build but higher gain amps can be tough to make quiet and not buzz/fizz.
Stay tune, I am making a one watt fumble style amp. There will be a video of it soon.
Hi Mike, I live in van. Can u build me a really simple 1 watt tube amp with an effects loop for 200 dollars
Hello, unfortunately, $200 would barely cover the cost of the parts. The issue is that I have to purchase everything retail and pay for shipping. You should give it a try.
Check out the Wang VH-T1
Is there a schematic posted anywhere? Thanks
Yes, link in the description.
Use copper strings with magnets glued on the strings because I'm the anti guitar guy who never had patience to learn guitar because I didn't think stealing someone's girlfriend as a fake rock star was worth it long term.
I made most of the circuit with parts hanging in the air just to see how fast I could make it on those white multi connector legs with screws.
Smashing a guitar into an amp would be my ultimate high/townsend/moon.
The links in the description of this video do not work.
The links open for me. Perhaps update or try a different browser. If not, I can email them to you if you like.
do you have a full parts list?
Hello, not yet. I’m still tweaking a few things. There is a link to the build schematic in the Description section. This is what I used to build the amp in the first two videos. The Part 3 video will wrap everything up. Cabinet and final schematic and parts list.
What will happen if you plug it into a European mains line (230VAC 50Hz)?
Will it blow up?
Probably... you will be basically doubling your b+ voltage. You need to source a power transformer rated for 230vac.
@@MikeFreda Thank you
Hey Mike, if you were to safely add an FX loop to your schematic, where would it be?
Hello, you can but I’m not sure it is worth modifying the circuit to make it work. You sort of lose the champ/Princeton vibe of the amp. It’s has a simplified topology where you can just input the effects right at the input Jack. You can look on the net for people who have done it. The front end of this amp is pretty much a 5F1 Champ. Some have put it between the two preamp stages or just before the power tube stage. I have not clue what would sound best or it if actually works since I’ve never done it. I hope that helps a bit?
@@MikeFreda thanks, you make a valid point.
So yeah, it makes sense to keep this amp as simple as possible. Or, if I need something more versatile, go fore a Tweed Deluxe build. Except I'm not sure that one has an fx loop either. Not in early versions for sure.
Most of the earlier tube amps (40’s to early 60’s) did not. Effects weren’t a thing back then due to solid state components weren’t really invented yet and people wanted a clean sound…. It’s wasn’t till the 60’s effects started to take off. All the tweed amps are basic topology based from the 40’s and 50’s.
@@MikeFreda yup. I once had the bright idea of experimenting with turning an old Soviet tube radio into a guitar amp, looked at the schematic and the damn thing creeped me out. Wasn't too keen on having tube high voltage rails on common ground with the guitar, because the transformer didn't have separate leads to isolate those. In our business, the first thing you learn is to respect high voltage, least it's the last thing you learn to respect.
I wish u had a discord
what if our PLN 220v? tm
Sorry, I don’t understand what you are asking me.
@@MikeFreda thnk you
Are you asking me about 220vac line voltage? If so, Hammond Transformer make a dual primary voltage power transformer. I think it’s their 300’s series.
Would you please confirm - is a 12BH7 in push-pull configuration 5 watts, rather than one watt?
Thanks for commenting, a 12BH7 in a single SE configuration would only give you ~1/3 of a watt depending how it is biased. In a Push/Pull or Parallel SE configuration you would only get around 1 watt. These tubes weren't really designed for this sort of application but people have figured out of the years that it can handle this duty. If you want more power, you will need a use a dedicated power tube like a 6V6 or a EL84. Cheers
@@MikeFreda thanks Mike for confirming.
I asked only because on the Blackstar HT5 they use a 12BH7 to get 5W.
I wasn't sure how the whole thing worked…
You’re welcome. I suspect that is a bit of a marketing ploy. 1watt RMS without clipping is different than 5watt peak at a higher frequency range. They don’t really say how or what their measurement is. Realistically, to your ear, the difference between 1 watt RMS and 5 watt peak is not a lot. Cheers.
EXCELLENT BUT WHY WOULD YOU SPEND ALL THAT TIME AND HARD WORK FOR ONE WATT? WHY NOT A NICE 40 OR 50?
Thanks for the comment. I wanted a low power practice/recording amp. I have made a couple larger amps and I find I don’t play them much. Also, larger amps do cost a lot more to make. The transformers and tubes cost twice as much. This video was also trying to show people that you can morph circuits and make your own creation.
@@MikeFreda THANK YOU FOR THE REPLY IS IT POSSIBLE TO UP THE WATTAGE ON THIS BUILD IF YOU WANTED TO?
Yes, just build the Fender Champ or Princeton version with a 6V6 output tube. 5watts which is more than enough for house volumes.
Why does it always look so easy when someone else is doing it?
It is and it isn't. My first builds were pretty messy and a bit of a rats nest but you only get better by doing. What you see me doing is 20+ years of building things. Just do it. Learn, improve and have fun.
PART 2: ruclips.net/video/IAqMCp7-oGQ/видео.html